Locking means for chain door guards



. Nov. 3, 1964 E. w. NORTH ETAL LOCKINGMEANS FOR cx-mm oooa GUARDS Filed Sept. 1, 1951 United States Patent 3,155,410 LOCKING MEAN FOR CHAIN DOOR GUARDS Edwin W. North and Carroll V. Span, Rockford, Ill.,

assignors to National Lock C0., Rockford, 111., a corporation of Delaware Filed Sept. 1, 1961, Ser. No. 135,663 11 Claims. (Cl. 292-264) The present invention relates to improvements in a novel chain door guard and more particularly to a novel locking means for a chain door guard to prevent the unauthorized release of a slide member in a slide bracket.

The common chain door guard in use today involves a support bracket and a slide bracket; one of which is secured to the interior of the door frame and the other is secured to the interior of the door adjacent the frame. A locking chain is either rigidly or detachably secured to the support bracket at one end and the opposite end terminates in a slide member which is inserted into an enlarged end of a slot in the slide bracket and slides in the slot due to an undercut groove in the slide member. When the slide member is in the end of the slot opposite the enlarged end of the latter, the door can be opened to a limited extent depending on the length of the chain, and it is intended that the chain can only be released from the slide bracket when the door is closed, and then only from the interior of the door.

However, it has been found that in some ingenious way intruders, after opening the door a limited amount per.- mitted by the chain, have been able to move the chain with its slide member suficiently to release the latter from the slot and thus open the door to obtain access to the home or other building.

The present novel assembly provides an added measure of safety in preventing unauthorized intruders from releasing the chain door guard and gainingaccess into a home or other building so protected.

The present invention retains the advantages found in the prior chain door guards and adds the further features of a locking means in the slide bracket to prevent the release of the slide member and its connected chain from the slide bracket by preventing access to the enlarged opening in one end of the slot. The locking means includes a projection or obstruction extending from a locking member into the slot to normally obstruct the path of movement of the slide member in the slot as it is moved toward the enlarged end of the slot. To release the slide member, this projection is manually moved out of the path of the slide member by manually operating the lock:

ing means.

An important object of the present invention is the provision of a movable or reciprocable locking means in the slide bracket of a chain door guard. The locking means includes a slidable locking member movable in a direction perpendicular to the longitudinal slot in the slide bracket. The locking member includes a lateral projection which in the normal locking position extends into the path of movement of a slide member on the end of the locking chain. The locking member is located adjacent to and its projection disposed ahead of the enlargedend of the slot to prevent release of the slide memher from the slot until suchprojection is intentionally moved out of the path of the slide member.

Another important object of the present invention is the provision of a novel locking means for a locking chain which is manually actuable to release the chain. A lateral tab at one end of the locking member is provided so that the user can easily lift or vertically move the locking member and thereby move the lateral projection out of the path of the slide member. The lateral projection also limits the extent of movement of the locking member so that the latter cannot be accidentally moved from its slide bracket.

A further object of the present invention is the provision of a novel slide bracket provided with a channel within which the locking member is allowed to move. The channel is of such dimensions that the locking member is free to move under the force of gravity to one of its two positions.

The present invention further comprehends the provision of one form of novel locking member which is normally in its locking position with the lifting tab abutting the upper edge of the slide bracket. When the locking member is lifted to release the slide member, gravity tends to return the locking member to its normal position.

The present invention also comprehends the provision of another form of locking member which is biased to its normal locking position by a resilient compression spring, and is lifted to its open or inoperative position against the force of the spring.

The present invention further comprehends the provision of a further modified form of a locking member having the lifting tab below and normally spaced from the slide bracket. To prevent the locking projection from dropping below the slot, a tab extending from the side of the locking member is spaced below the locking projection to limit downward movement of the frictionally mounted locking member with the locking projection in its locking position.

Further objects are to provide a construction of maximum simplicity, cificiency, economy and ease of assembly and operation, and such further objects, advantages and capabilities as will later more fully appear and are inherently possessed thereby.

In the drawing:

FIGURE 1 is a front elevational view of the novel chain door guard as attached to the interior of a door and door frame showing one embodiment of the locking means on the slide bracket and with the chain in operative locking position and the door closed.-

FIG. 2 is a bottom plan view of the slide bracket shown in FIG. 1 and showing the mounting of the locking member but with the slide member and chain removed.

FIG. 3 is a front elevational view of the locking member shown in FIGS. 1 and 2.

FIG. 4 is a side elevational view of the locking member of FIG. 3.

FIG. 5 is a side elevational view of the slide member which is attached to one end of the chain.

FIG. 6 is a partial front elevational view of another embodiment of alocking member in the slide bracket including a resilient compression spring.

FIG. 7 is a front elevational view of the locking member of FIG. 6.

Y ber of FIG. 7.

FIG. 9 is a partial front elevational view of a third embodiment of locking member mounted in the slide bracket.

, Referring more particularly to the disclosure in the drawing in which is shown the illustrative embodiments of the present invention, FIG. 1 discloses the novel chain door guard assembly 10 secured to a door frame 11 and its associated door 12. The door guard 10 includes a bracket 13 secured to the door frame 11, a slide bracket 14 secured to the door 12 and a chain 15 detachably connected to the brackets 13 and 14 to limit the extent of opening the door.

The bracket 13 shown in FIG. 1 .is the subject of our patent application Serial No. 121,094, filed June 30, 1961,

now Patent No. 3,l0l,603, and includes an opening into a secured to the supporting structure.

which a slide member 16 can be inserted and secured by a locking plate (not shown) and a tumbler lock 17 which when actuated by a proper key shifts the locking plate to release and permit removal of its slide member 16. More complete details of the bracket assembly are shown in our copending application cited above. It should be understood that this locking bracket is not essential to the present invention as the chain 15 may be rigidly secured at one end to any common bracket presently used for a chain door guard.

The slide bracket 14 (FIG. 1) comprises a substantially rectangular plate 18 having openings 19 adjacent the corners for the reception of suitable securing means.

21. A longitudinally extending substantially rectangular raised portion or embossment 22 is provided on the plate 18 and has a longitudinally extending slot 23 with an enlarged opening 24 at the end of the slot farthest from the juncture of the door 12 and the door frame 11. The chain 15 is composed of a series of interlinked loops or links joined at each end 25 to a slide member 16. Ohviously, if the chain is rigidly secured to the bracket 13. only one slide member 16 is provided and this on the free end of the chain.

Each slide member 16 includes a knob 26 having a stepped shank 27 extending therefrom, and a lock bushing 28 having a central opening 29 to accommodate the shank 27 (FIG. The opening 29 is counterbored to receive the enlarged portion 31 of the shank 27 to space the bushing 28 from the knob 26. The bushing is formed with a flange 32 adjacent the knob and a body having an annular groove 33 formed therein and spaced from the flange. The inner end of the bushing is chamfered or tapered as at 34 for guiding it into the opening 24 at one end of the slot 23, and the knob and bushing are retained assembled by deforming or riveting the end of the shank 27. The end link 25 of the chain is received around the enlarged shank portion 31 between the knob 26 and the flange 32.

A channel 35 open at its opposite ends and at the back is formed in the back of the slide bracket 14 (FIG. 2), where it abuts the door or support to which the bracket is secured leaving a sufiicient opening between the slide bracket and the surface to receive the locking member 36 and allow freedom of movement. The channel 35 is oriented perpendicular to the longitudinal axis of the slide bracket 14 and arranged adjacent the enlarged opening 24 at the end of the slot 23. The locking member 36, as more clearly shown in FIGS. 3 and 4, has a flat body 37 conformably received within the channel 35 and an upper lateral tab or flap 38 for lifting and moving the member 36. From an opening 33 in the locking member is stamped a tongue bent at a right angle to the body 37 to form a lateral locking projection 41.

As shown in FIG. 1, the locking member 36 is positioned in the channel 35 and the slide bracket 14 is then The locking member 36 is normally urged downward to locking position by gravity so that the tab or flap 38 abuts the edge of the bracket 14 with the lateral locking projection 41 positioned substantially centrally of the slot 23 to form an abutment thereat. To release the slide member 16 on the chain 15 from the slot 23, the flap 38 is lifted until the projection 41 abuts the interior surface of the elevated portion 22 and the slide member can then he slid or moved to the enlarged opening 24 and withdrawn therethrough. Releasing the flap 38 allows the locking member 36 to return to its normal locking position.

A second embodiment of a locking means 42 for the slide bracket is shown in FIGS. 6, 7 and 8. There the slide bracket 14 has a channel 35 for-med in the underside or back of the bracket and between the latter and the door or support to accommodate the body 43 of the locking member 42 (FIGS. 7 and 8). A secondary elevated portion 44 is formed in the slide bracket laterally of and joining the rectangular raised portion 22 and over the channel 35 This secondary raised portion 44 houses a compression spring 45 with one end of the spring seated upon the upper closed end 46 of the elevated portion 44. The spring extends into the elevated portion 22 and into contact with and urges the locking member 42 downwardly into locking position.

The locking member 42 comprises the flat body 43 and a lateraly projecting tab 47 for manually lifting and moving the locking member. Stamped from the opening 48 is a lateral extension 49 bent to form an upward projection 51 having a reduced end 52 receiving the opposite end of the compression spring 45 to urge the locking member downwardly into its locking position. This embodiment operates in the same manner as the locking means shown in FIGS. 1 to 4, except when the lifted locking member is released the compression spring 45 positively urges the member 42 to its normal locking position.

A third embodiment of locking means is disclosed in FIG. 9 where the slide bracket 14 is formed with a channel 35 like the channel 35 shown in FIGS. 1 and 2. The locking member 53 has a flat body portion 54 and a laterally extending lifting tab 55 positioned on the lower end of the member 53. Stamped from an opening 56 is a locking projection 57 extending laterally therefrom and normally positioned to obstruct the slot 23 A second projection or tab 58 extending from one side of the locking member 53 provides a stop which prevents the member 53 from dropping below its normal locking position by the stop abutting the side of the elevated portion 22 when the member 53 is in its locking position.

The upper edge 59 of the locking member 53 is aligned with the edge of the slide bracket 14* and the lifting tab 55 is spaced from and below the bracket in normal position (FIG. 9); To release slide member 16 from the slot 23 the tab 55 is manually lifted thereby removing the locking projection from the slot 23 and the path of the slide member 16. Upon release, the locking member 53 returns to the locked position under the force of gravity.

Having disclosed the invention, we claim:

1. In combination with a chain door guard having a slide bracket to be aflixed to a door and a slide member aflixed to one end of a chain with the other end of the chain anchored to the door frame, said slide bracket having a longitudinal slot with an enlarged opening at one end adapted to receive the slide member which is slidably retained in the slot, the rear of said slide bracket provided with a channel extending across and at the rear of said slot forwardly of said opening, and a locking member slidably mounted in said channel and having a pro jection movable into and out of the path of said slide member and when in the path of said slide member preventing the latter from being withdrawn from said slot through the opening.

2. Locking means for a chain door guard comprising a slide bracket having an elongated slot for receiving a slide member afiixed to one end of a chain, said bracket having an elevated portion provided with said elongated slot terminating, at one end in an enlarged opening, a channel formed in the back of said bracket, a slidable locking member in said channel including a fiat body, a lifting tab at one end of said body and a lateral locking projection extending into the path of said slide member in said elongated slot when said locking member is in normal locking position.

3. Locking means for a chain door guard as set forth in claim 2, in which said locking member is slidable between a normal locking position and an unlocked position.

4. Locking means for a chain door guard as set forth in claim 2, in which said lateral locking projection when in looking position extends into the path of said slide member in said elongated slot and adjacent said enlarged opening to prevent withdrawal of said slide member through said opening.

projection abutting the internal surface of the elevated portion of said bracket.

6. Locking means for a chain door guard comprising a slide bracket for a slide member of a chain door guard, an elevated portion of said bracket having an elongated slot therein for receiving the slide member and terminating at one end in an enlarged opening through which the slide member is inserted and removed from the slot, a channel formed in the back of said bracket, a slidable locking member in said channel, said locking member including a flat body, a lateral lifting tab at one end of the body and a centrally positioned laterally and upwardly extending locking projection movable into the path of the slide member, a secondary elevated portion on said bracket extending perpendicularly to and merging into said elevated portion of said bracket, and resilient means in said secondary elevated portion urging said locking member into locking position.

7. Locking means for a chain door guard comprising a slide bracket for a slide member secured to a chain, a centrally located elongated elevated portion of said bracket having an elongated slot therein for receiving the slide bracket and terminating at one end in an enlarged opening through which the slide member is inserted and removed from the slot, a channel formed in the back of said bracket, a slidable locking member received in said channel, said member including a flat body, a lateral lifting tab at the lower end of said locking member, a centrally positioned lateral locking projection on said locking member and normally extending into the path of the slide member in the elongated slot, and means to limit the movement of said locking member.

8. Locking means for a chain door guard as set forth in claim 7, in which said limiting means includes a projection extending from the side of the flat body of the locking member and abutting the internal surface of said elevated portion of the bracket when said locking member is in locking position.

9. A chain door guard having a chain attached at one end to a door frame and at its other end detachably connected to a door, comprising a slide bracket secured to the door and having a longitudinal slot therein with an enlarged opening in one end, a chain having a slide member received in said opening and slidable in said slot for limiting the extent of opening of the door, said slide bracket being provided with a channel disposed at the rear of and perpendicular to said slot, and a locking member slidably mounted in said channel adjacent said enlarged opening and having a projection movable into and out of the path of the slide member in said slot, said projection when moved into the path of said slide member preventing removal of the slide member from its slot, said locking member having a manually actuated tab at its upper end for moving said projection into and out of the path' of said slide member in the slot.

10. A chain door guard having a chain attached at one end to a door frame and at its other end detachably connected to a door, comprising a slide bracket secured to the door and having a longitudinal slot therein with an enlarged opening in one end, a chain having a slide member received in said opening and slidable in said slot for limiting the extent of opening of the door, a locking member slidably mounted and movable transversely of the slot in said slide bracket adjacent said enlarged opening, said locking member being out of the path of said slide member, and a lateral locking projection on said locking member and normally extending into the path of the slide member preventing removal of the slide member from said slot, said locking member and lateral projection having limited reciprocation to move said projection out of the path of the slide member.

11. Locking means for a chain door guard comprising a slide bracket having an elongated slot for receiving a slide member afiixed to one end of a chain, said bracket having an elevated portion provided with said elongated slot terminating at one end in an enlarged opening, a locking member slidably mounted in said bracket including a flat body, a lifting tab at one end of said body and a lateral locking projection extending into the path of said slide member in said elongated slot adjacent said enlarged opening when said locking member is in normal locking position, said locking member having limited reciprocation between its normal locking position and an unlocked position where said lateral projection engages the internal surface of the elevated portion of said bracket.

References Cited in the file of this patent UNITED STATES PATENTS 401,977 Spooner Apr. 23, 1889 1,492,030 Grah Apr. 29, 1924 2,105,714 West I an. 18-, 1938 

1. IN COMBINATION WITH A CHAIN DOOR GUARD HAVING A SLIDE BRACKET TO BE AFFIXED TO A DOOR AND A SLIDE MEMBER AFFIXED TO ONE END OF A CHAIN WITH THE OTHER END OF THE CHAIN ANCHORED TO THE DOOR FRAME, SAID SLIDE BRACKET HAVING A LONGITUDINAL SLOT WITH AN ENLARGED OPENING AT ONE END ADAPTED TO RECEIVE THE SLIDE MEMBER WHICH IS SLIDABLY RETAINED IN THE SLOT, THE REAR OF SAID SLIDE BRACKET PROVIDED WITH A CHANNEL EXTENDING ACROSS AND AT THE REAR OF SAID SLOT FORWARDLY OF SAID OPENING, AND A LOCKING MEMBER SLIDABLY MOUNTED IN SAID CHANNEL AND HAVING A PROJECTION MOVABLE INTO AND OUT OF THE PATH OF SAID SLIDE MEMBER AND WHEN IN THE PATH OF SAID SLIDE MEMBER PREVENTING THE LATTER FROM BEING WITHDRAWN FROM SAID SLOT THROUGH THE OPENING. 